import java.util.Scanner;

public class homeWork5 {
    public static int factoRial(int n){
        int tot = 1;
        for(int i=1;i<=n;i++){
            tot*=i;
        }
        return tot;
    }
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        int n;
        while(input.hasNextInt()){
            n=input.nextInt();
            int a = factoRial(n);
            System.out.println(n+"的阶乘是："+a);
        }
    }
}
